The Arch of Hadrian stands at the southern entrance to the Jerash site, a triple-arched triumphal gateway built to commemorate the Emperor Hadrian's visit to the city in 129–130 AD. At 13 metres high with its upper sections largely intact, it is one of the better-preserved triumphal arches of the Roman east.
The arch is the first major monument you encounter when entering the site from the main ticket office, and it sets the scale for everything that follows. The decoration — pilasters with Corinthian capitals, carved corbels that once supported statues — is detailed and well-preserved on the interior faces. The arch originally marked a proposed extension to the city's southern boundary, an expansion that Gerasa's later decline made unnecessary.